Process of distillation.



PATENTED NOV. 21, 1905.

G. H. BRADFORD. PROCESS OF DISTILLATION.

urmonmn FILED AUG. 20, 1903.

UNITED'STATES PATENT OFFICE.

GEORGE BRADFORD, OF STOCKTON, CALIFORNIA, ASSIGNOR TO JOHN TREADWELL, OF SAN FRANCISCO, CALIFORNIA.

PROCESS OF DISTILLATION.

Specification of Letters Patent.

Patented Nov. 21, 1905.

Application filed August 20, 1903. Serial No. 170,223.

1'0 aZZ whOm it may concern.-

' Be it known that I, GEORGE H. BRADFORD, a citizen of the United States, residing at Stockton, in the county of San Joaquin and State of California, have invented certain new and useful Improvements in Processes of Distillation, of which the following is a specification.

My invention relates to the distillation of crude petroleum for the obtaining of various distillates and the asphaltic or other residuums left after such distillates have been given The object of my invention is to make a complete separation of the vapors from the oil without carrying over into the condenser either oil or water, so that when condensed the distillates are of full strength and full value.

Generally speaking, my improved process consists in raising the vapors drawn from the still to a greater height than the height to which the liquid being distilled can rise in a vacuum before passing them into the condenser.

In the accompanying drawing I have illustrated an apparatus for practically carrying out my process in order that the following description may be more intelligible.

The drawing shows a general elevation or assemblage of enough of the parts constituting a distilling system to clearly illustrate my invention and includes the still,the vaporpipe leading therefrom. the condenser, and a vacuum-pump for drawing the vapors from the still.

The still 1 may be of any preferred construction and can be heated in any preferred manner, as by a furnace or an oil-burner beneath. The vapor-escape pipe 2 instead of leaving the still at about its upper level and then going directly to the condenser leaves the still vertically, so as to form an elevated returning-leg 3, whose extreme height is greater than the height to which the liquid being distilled can rise in a vacuum-that is to say, the height of the pipe is calculated according to the ratio which aweight of water bears to the weight of the material under distillation. Thus if the weight of water is eight and one-third pounds per gallon and that of oil siX and one-half pounds per gallon a proper height for the leg in ordinary use would be from forty to fifty feet. The returnleg of this pipe is connected into the suction of an ordinary vacuum-pump 4, which discharges into a condenser 5, where the vapors are condensed and thence run into tanks or receptacles for the distillates.

The height given for the vacuum-leg is not arbitrary and may be varied according to the specific gravity of the material in the still. The height given has been found proper and practical in the distillation of heavy California oils having an asphaltie base; but in every instance in distilling oils the height must be greater than that to which the liquid being distilled can rise in a vacuum.

In carrying out the process as the still is heated and the vacuum-pump started a vacuum is formed in the upper part of the still and in the leg, so that the vapors as they begin to be given off pass up the leg and thence to the vacuum-pump and condenser. Obviously no oil or Water can be carried over, and hence only the pure oil-vapors reach the condenser. The result is that the distillates produced are one hundred per cent. pure instead of less than seventy-five per cent. pure in vacuum processes as now used.

WVhe-re my process of elevating the vapors to a considerable height-that is, to a height greater than that to which the liquid being distilled can rise in a vacuumis employed it has been found in practice that only vapors pass into the pump and that the fouling of the pump by the admission of heavy liquid material is entirely prevented.

Having thus fully described my invention, what I claim as new, and desire to secure by Letters Patent, is

1. The vacuum process of distilling, which consists in drawing the vapors of distillation to a height greater than the height to which the liquid being distilled can rise in a vacuum, and then delivering such vapors to a condenser.

2. The process of distilling which consists in forming an elevated vacuum above the still extending to a height greater than the height to which the liquid being distilled can rise in a vacuum whereby the vapors produced by distillation are drawn upwardly into said elevated vacuum before being delivered to the condenser.

In testimony whereof I have affixed my signature, in presence of two witnesses, this 1st day of August, 1903.

GEORGE H. BRADFORD.

WVitnesses:

F. M. BURT, L. WV. SEELY. 

